I would imagine the point was that we don't know where the father was from. He may be a Manc, in which case I think it's not plastic to bring his kids up supporting them. When I was in Liverpool I taught my kids all about the Albion, their history and bought them Brighton stuff. They could have been Liverpool fans, did that make them plastic Brighton?
Of course it didn't make them plastic Brighton fans.
Shall we change plastic for 'glory hunters' just for you
Go and argue with someone else about the colour of Orange juice .